CHANNAHON, Ill. (CBS) — An Oswego police officer has been suspended after walking into a southwest suburban pizzeria with a gun, and yelling at employees while off duty.

Channahon police said 43-year-old Oswego police officer John Wolfinbarger had a gun in his waistband when he walked into Chicago Pizza, at 25520 S. Pheasant Ln., and began arguing with an employee around 5:30 p.m. on Wednesday.

He didn’t pull out the gun, but customers didn’t know he was an officer, and were scared, so they called police.

By the time Channahon police arrived, Wolfinbarger had left the restaurant and gotten into his pickup truck and started driving away.

Officers pulled over Wolfinbarger’s truck, but he refused to cooperate with police and rolled up his window.

When the officers tried to coax him out of the truck, he tossed his wallet out the window and challenged officers to come get it.

Officers held the man at gunpoint for about 20 minutes before he surrendered.

He never told police he was an Oswego police officer.

Wolfinbarger has been charged with drunk driving, disorderly conduct, and obstructing police. He also has been placed on administrative leave.